Let's Make Robots!

coil gun s

hay guys, im thinking of making a coil gun, and im just woundering What capacitors are best?

the coil gun is just meant to be small not that powerfull.

also this is what im thinking for the setup - battery's power a dc/dc converter which, charge capacitor banks which is then dumped in to the coils ( a piaxe controls the timing of the coils )etc .

an comments are appreciated 

Thanks

 

K243 high power dc speed controller , trouble

well, i bought a couple of speed controllers a year or 2 ago ( same ones oddbot's Boozebot used )

http://secure.oatleyelectronics.com//product_info.php?cPath=94&products_id=206&osCsid=97e420b

and i had them working with the 10k trimpot, but when trying to control them with arduino it wont work 

mysetup: 9v battery to +,- on the screw terminals , arduino pin to sig, motors attached correctly , and secondary power supply on mtr+,gnd

any suggestions?

update: 

 this is my first robot using arduino , it uses a l239d motor driver and is basicaly my atempt at making a start here robot . Parts list : 1) arduino starter pack … Read more

motors and amps

hay, during building first robot i had some difficulties with my power source , my setup was basicaly a start here robot but with arduino  i used the l239d motor driver , my power supply was a ni-mh 9v rechargeable battery powering arduino, and 3 AA battery pack to the motor driver

THE PROBLEM: 

my problem was my motors runing weakly, or slowly ( they are gm8 solarbotics motors ), this did inprove slightly when i switched to the battery source mentioned above .

THE QUESTION:

arduino code probs(again)

ok the motor code works fine now, but now i added, some of the 2-10cm infrared sensors ,and the code just drives forward, as if it doesnt see the infrared? any help would be appreciateted ,here is the code

int infra=3;
int value = 0 ;
int infra2=4;
int val2= 0;

void setup()
{
  Serial.begin(9600);
  pinMode(13,OUTPUT);
 pinMode(12,OUTPUT);
  pinMode (11,OUTPUT);
  pinMode (10,OUTPUT);
  pinMode (3,INPUT);
  pinMode (infra,INPUT);
}
 
 
NEW: the first 2 parts work the third doesnt 

arduino code not working the way it should

i made a code ,and the code doesnt work the way it should, it makes the motors go bakwards ,pause, backwards

this isnt what i told it to do, why is this so here is the code , hope you can help cause i want to enter this in the arduino challenge

hello , this is my first robot , it is intended to be a long term project  kinda like CtC s WALTER , so far i only have the motors and motor drivers . Read more

pwm on a picaxe

hay i was woundering if there is a picaxe board that can control the speed of 4 normal dc motors, ive looked but i cant seem to find a picaxe with 4 pwm channels,i think the 28x2 has something similar that has 4 channels but im not sure, any help would be appriciated.

dont worry found a solution

van da graf?

hay woundering if its possible to power a robot with van da graf generators?

servo motor conrol

hay woundering if any one knows of a good servo motor controller and how to use it?